Isadora

From the experts:

Why is Isabella megapopular while Isadora goes virtually ignored? Too close a tie with tragic modern dancer Isadora Duncan (born Angela Isadora), who was done in by her long flowing scarf, perhaps, or with fusty male version Isidore. But we think Isadora is well worth reevaluating as an Isabella alternative. Quirky couple singer Bjork and artist Matthew Barney did just that and named their daughter Isadora. Isidora would be an alternative, just as proper but not quite as charming spelling--the one used as the spelling of a fourth century saint's name.

Isadora Wing was the liberated central character of Erica Jong's 1973 bestseller Fear of Flying. There is also Isadora Quagmire in Lemony Snicket's A Series of Unfortunate Events--who was named for Isadora Duncan.

And she could share the nickname Izzy with cousin Isabella.